Multistage transmission

Abstract

A multistage transmission in planetary design is proposed, comprising a basic transmission ( 8 ) and a group transmission ( 9 ) downstream of the basic transmission ( 8 ), wherein the basic transmission ( 8 ) comprises three planetary gear set (P 1 , P 2 , P 3 ), at least six rotatable shafts ( 1, 2, 3, 4, 5, 6 ) and at least five shift elements (A, B, D, E, F), the selected engagement of which results in different transmission ratios between the input drive and the output drive, wherein the group transmission ( 9 ) has a minus planetary gear set (P 4 ), the sun gear of which is connected to the output shaft ( 2 ) of the basic transmission ( 8 ), the ring gear of which can be coupled to the housing (G) via a first shift element (K 1 ), and the carrier of which is connected to the output shaft ( 7 ) of the multistage transmission, which can be releasably connected to the ring gear via a second shift element (K 2 ), and wherein the basic transmission ( 8 ) and the group transmission ( 9 ) are disposed in a common housing (G).

The invention claimed is: 
     
       1. A multi-stage automatic transmission of a planetary design for a motor vehicle, the multi-stage transmission comprising:
 a basic transmission ( 8 ) and a group transmission ( 9 ) located downstream of the basic transmission ( 8 ); 
 the basic transmission ( 8 ) comprising:
 first, second and third planetary gear sets (P 1 , P 2 , P 3 ) and each of the first planetary gear set (P 1 ), the second planetary gear set (P 2 ) and the third planetary gear set (P 3 ) comprising a sun gear, a ring gear and a carrier; 
 at least a drive shaft ( 1 ), an output shaft ( 2 ) and third, fourth, fifth and sixth rotatable shafts ( 3 ,  4 ,  5 ,  6 ); 
 at least five shift elements (A, B, D, E, F) whose selective engagement implementing different transmission ratios between the drive shaft and the output shaft; and 
 
 the group transmission ( 9 ) comprising:
 a minus planetary gear set (P 4 ) having a sun gear, a ring gear and a carrier, the sun gear of the minus planetary gear set (P 4 ) being continuously connected to the output shaft ( 2 ) of the basic transmission ( 8 ), 
 the ring gear of the minus planetary gear set (P 4 ) being connectable, via a first shift component (K 1 ), to a housing (G), 
 the carrier of the minus planetary gear set (P 4 ) being continuously connected to a drive output shaft ( 7 ) of the multi-stage transmission, and 
 the ring gear of the minus planetary gear set (P 4 ) being connectable, via a second shift component (K 2 ), to the drive output shaft ( 7 ), and 
 
 the housing (G) housing both the basic transmission ( 8 ) and the group transmission ( 9 ) within a common housing. 
 
     
     
       2. The multi-stage transmission according to  claim 1 , wherein the basic transmission ( 8 ) is implemented such that
 the drive shaft ( 1 ) is continuously connected to the sun gear of the first planetary gear set (P 1 ) and the drive shaft ( 1 ) is connectable, via a first clutch (A), to the sixth shaft ( 6 ), and the drive shaft ( 1 ) is connectable, via a second clutch (B), to the fifth shaft ( 5 ); 
 the output shaft ( 2 ) of the basic transmission ( 8 ) is continuously connected to the carrier of the third planetary gear set (P 3 ); 
 the third shaft ( 3 ) is continuously connected to the ring gear of the first planetary gear set (P 1 ) and is connectable, via a first brake (D) to the housing (G); 
 the fourth shaft ( 4 ) is continuously connected to the carrier of the first planetary gear set (P 1 ) and the ring gear of the second planetary gear set (P 2 ), and the fourth shaft ( 4 ) is connectable, via a second brake (E), to the housing (G); 
 the fifth shaft ( 5 ) is continuously connected to the carrier of the second planetary gear set (P 2 ) and to the ring gear of the third planetary gear set (P 3 ), and the fifth shaft ( 5 ) is connectable, via a third brake (F), to the housing (G); 
 the sixth shaft ( 6 ) is continuously connected to the sun gear of the second planetary gear set (P 2 ) and the sun gear of the third planetary gear set (P 3 ); and 
 the first clutch (A), of the basic transmission ( 8 ), is implemented as one of a form-locking shift element and a multi-disk shift element, and the second clutch (B), the first brake (D) and the second brake (E) of the basic transmission ( 8 ) are implemented as multi-disk shift elements. 
 
     
     
       3. The multi-stage transmission according to  claim 2 , wherein the second shift component (K 2 ), of the group transmission ( 9 ), releasably connects the drive output shaft ( 7 ) of the multi-stage transmission to the ring gear of the minus planetary gear set (P 4 ) of the group transmission ( 9 ), and the second shift component (K 2 ) is a multi-disk shift element for ensuring that the group transmission ( 9 ) is shiftable under load, and the first shift component (K 1 ) of the group transmission ( 9 ) is one of a multi-disk shift element and a form-locking shift element. 
     
     
       4. The multi-stage transmission according to  claim 3 , wherein the multi-stage transmission can implement nine forward gears,
 a first forward gear is implemented by engagement of the first clutch (A) and the third brake (F) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a second forward gear is implemented by engagement of the first clutch (A) and the second brake (E) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a third forward gear is implemented by engagement of the first clutch (A) and the first brake (D) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a fourth forward gear is implemented by engagement of the first clutch (A) and the second clutch (B) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a fifth forward gear is implemented by engagement of the first clutch (A) and the second brake (E) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 a sixth forward gear is implemented by engagement of the first clutch (A) and the first brake (D) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 a seventh forward gear is implemented by engagement of the first clutch (A) and the second clutch (B) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 an eighth forward gear is implemented by engagement of the second clutch (B) and the first brake (D) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 a ninth forward gear is implemented by engagement of the second clutch (B) and the second brake (E) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ), and 
 upward and downward gear changes, between the first and the second forward gears, the second and the third forward gears, the third and the fourth forward gears, the fourth and the fifth forward gears, the fifth and the six forward gears, the sixth and the seventh forward gears, the seventh and the eighth forward gears, and the eighth and the ninth forward gears are shiftable under load. 
 
     
     
       5. The multi-stage transmission according to  claim 3 , wherein the multi-stage transmission can implement eight forward gears,
 a first forward gear is implemented by engagement of the first clutch (A) and the third brake (F) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a second forward gear is implemented by engagement of the first clutch (A) and the second brake (E) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a third forward gear is implemented by engagement of the first clutch (A) and the first brake (D) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a fourth forward gear is implemented by engagement of the first clutch (A) and the second clutch (B) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a fifth forward gear is implemented by engagement of the second clutch (B) and the first brake (D) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a sixth forward gear is implemented by engagement of the first clutch (A) and the second clutch (B) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 a seventh forward gear is implemented by engagement of the second clutch (B) and the first brake (D) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 an eighth forward gear is implemented by engagement of the second clutch (B) and the second brake (E) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ), and 
 upward and downward gear changes between the first and the second forward gears, the second and the third forward gears, the third and the fourth forward gears, the fourth and the fifth forward gears, the fifth and the six forward gears, the sixth and the seventh forward gears, and the seventh and the eighth forward gears are shiftable under load. 
 
     
     
       6. The multi-stage transmission according to  claim 2 , wherein the third brake (F) of the basic transmission ( 8 ) is implemented as a form-locking shift element, and control thereof, in implementation as a multi-disc shift element, is used for controlling the second shift element (K 2 ) of the group transmission ( 9 ). 
     
     
       7. The multi-stage transmission according to  claim 2 , wherein the second shift component (K 2 ) of the group transmission ( 9 ) releasably connects the drive output shaft ( 7 ) of the multi-stage transmission to the ring gear of the minus planetary gear set (P 4 ) of the group transmission ( 9 ) and is designed as a form-locking shift element, and the first shift component (K 1 ) of the group transmission ( 9 ) is one of a multi-disk shift element and a form-locking shift element. 
     
     
       8. The multi-stage transmission according to  claim 7 , wherein the third brake (F) of the basic transmission ( 8 ) is a form-locking shift element. 
     
     
       9. The multi-stage transmission according to  claim 7 , wherein the multi-stage transmission can implement nine forward gears,
 a first forward gear is implemented by engagement of the first clutch (A) and the third brake (F) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a second forward gear is implemented by engagement of the first clutch (A) and the second brake (E) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a third forward gear is implemented by engagement of the first clutch (A) and the first brake (D) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a fourth forward gear is implemented by engagement of the first clutch (A) and the second clutch (B) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a fifth forward gear is implemented by engagement of the first clutch (A) and the second brake (E) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 a sixth forward gear is implemented by engagement of the first clutch (A) and the first brake (D) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 a seventh forward gear is implemented by engagement of the first clutch (A) and the second clutch (B) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 an eighth forward gear is implemented by engagement of the second clutch (B) and the first brake (D) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 a ninth forward gear is implemented by engagement of the second clutch (B) and the second brake (E) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ), and 
 upward and downward gear changes between the first and the second forward gears, the second and the third forward gears, the third and the fourth forward gears, the fifth and the six forward gears, the sixth and the seventh forward gears, the seventh and the eighth forward gears, and the eighth and the ninth forward gears are shiftable under load, and two of the shift elements of the basic transmission ( 8 ) that are implemented as multi-disk shift elements of the basic transmission ( 8 ) synchronize the second shift component (K 2 ) of the group transmission ( 9 ) to reduce interruption of the tractive force. 
 
     
     
       10. The multi-stage transmission according to  claim 7 , wherein the multi-stage transmission can implement eight forward gears,
 a first forward gear is implemented by engagement of the first clutch (A) and the third brake (F) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a second forward gear is implemented by engagement of the first clutch (A) and the second brake (E) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a third forward gear is implemented by engagement of the first clutch (A) and the first brake (D) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a fourth forward gear is implemented by engagement of the first clutch (A) and the second clutch (B) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a fifth forward gear is implemented by engagement of the second clutch (B) and the first brake (D) of the basic transmission ( 8 ) and the first shift component (K 1 ) of the group transmission ( 9 ); 
 a sixth forward gear is implemented by engagement of the first clutch (A) and the second clutch (B) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 a seventh forward gear is implemented by engagement of the second clutch (B) and the first brake (D) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ); 
 an eighth forward gear is implemented by engagement of the second clutch (B) and the second brake (E) of the basic transmission ( 8 ) and the second shift component (K 2 ) of the group transmission ( 9 ), and 
 upward and downward gear changes between the first and the second forward gears, the second and the third forward gears, the third and the fourth forward gears, the fourth and the fifth forward gears, the sixth and the seventh forward gears, and the seventh and the eighth forward gears are shiftable under load. 
 
     
     
       11. The multi-stage transmission according to  claim 1 , wherein an electric machine is attached to the group transmission ( 9 ) such that the transmission ratio of the group transmission ( 9 ) serves as a reduction of the electric machine to increase torque of the electric machine. 
     
     
       12. The multi-stage transmission according to  claim 11 , wherein the electric machine is either connected or releasably connected to the sun gear of the minus planetary gear set (P 4 ) of the group transmission ( 9 ). 
     
     
       13. The multi-stage transmission according to  claim 1 , wherein an electric machine is connected, in a tractive mode, downstream of the group transmission ( 9 ), in a direction of power flow, and a rotor of the electric machine is either connected or releasably connected to the carrier of the minus planetary gear set (P 4 ) of the group transmission ( 9 ). 
     
     
       14. The multi-stage transmission according to  claim 1 , wherein the third brake (F) of the basic transmission ( 8 ) that is a form-locking shift element and the first and the second shift components (K 1 , K 2 ) of the group transmission ( 9 ) that are form-locking shift elements are controlled via an external control. 
     
     
       15. The multi-stage transmission according to  claim 1 , wherein the first, the second, and the third planetary gear sets (P 1 , P 2 , P 3 ) are minus planetary gear sets and are axially, sequentially arranged in an order of the first planetary gear set (P 1 ), the second planetary gear set (P 2 ) and the third planetary gear set (P 3 ).